Poor weather conditions may have contributed to the pre-dawn crash of a Troy-based medical helicopter that claimed the lives of all four people abroad.

Peter Knudson, a spokesman for the National Transportation Safety Board, said federal investigators are tying to determine what caused the chopper to crash in the Goodman area of Coffee County after picking up a patient from the scene of a highway crash.

“The weather as described as inclement, foggy,” Knudson said. “We will be getting more specifics about visibility and the weather conditions the helicopter would have been encountering.”

The crash claimed the lives of pilot Chad Hammond, flight nurse Stasi Cernadas, flight medic Jason Snipes and patient Zach Strickland. The Haynes Lifeflight crew was based at Troy Regional Medical Center.

The crew responded from Troy to the scene of a motor vehicle accident on County Road 615 in Coffee County, where a motorist struck a ditch and a utility pole in a one-car vehicle crash about 11 p.m. Friday, according to the state troopers.

The helicopter took off with the motorist from the scene was reported missing around 12:17 a.m. The wreckage was located shortly after 7 a.m. Saturday in a heavily wooded and marshy area. Recovery efforts were hampered by the weather over the weekend, and plans Monday called for recovery of the wreckage to begin.

“Once they are able to get the helicopter to dry, higher ground, they will work on documenting the components of the wreckage,” Knudsen said.

Metro Aviation Inc. of Shreveport, Louisiana, which operated the helicopter for an Alabama ambulance company, issued a statement Monday saying that the company “places safety at the top of our priority list” and that a company response team is assisting federal authorities with the investigation.

It will likely take several months or as much as a year or longer for the NTSB to determine the cause of the crash, Knudson said.

The loss rocked employees of Haynes Ambulance, which provides the Lifeflight service, and Troy Regional Medical Center, where the chopper was stationed.

Haynes owner Kirk Barrett said on Saturday the immediate focus is on caring for the families of the lost crew. On Sunday, the following message was posted on the Haynes Facebook page: “Words cannot explain the hurt that the HaynesLifeflight/ambulance are feeling. We would like to thank everyone for their support during these difficult times it is truly heart warming. Please continue to keep the families in your prayers as they have suffered a tremendous loss. Godspeed.”

At Troy Regional Medical Center, employees held a private memorial service on Monday.

“The Troy Regional Medical Center family is saddened today by the tragic loss of the Haynes helicopter crew members and the patient being transferred,” said TRMC CEO Teresa Grimes.

“We will be in prayer for their families as well as the Haynes ambulance and flight staff.”

Troy Mayor Jason Reeves said the accident was “a devastating loss for our community and for the many others in the area.

“Our thoughts and prayers go out to the families of the crew and patient who lost their lives as well as the hundreds of staff and first responders who work with Haynes hand-in-hand across the region,” he said. “We will continue to pray for those grieving this loss and those who place their lives in harm’s way daily to keep our communities safe.”

The Associated Press contributed to this story.